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122800

FEATURES

Provides real time clock:

− Counts seconds, minutes, hours, date of

the month, month, day of the week, and

year with leap year compensation valid up

to 2100

− Power control circuitry supports system

power-on from day/time alarm

Microprocessor monitor:

− Halts microprocessor during power fail

− Automatically restarts microprocessor

after power failure

− Monitors pushbutton for external override

− Halts and resets an out of control

microprocessor

NV RAM control:

− Automatic battery backup and write

protection to external SRAM

3-channel, 8-bit analog-to-digital converter

Simple 3-wire interface

3.3V operation

PIN ASSIGNMENT

Package Dimension Information can be found at:

http://www.dalsemi.com/datasheets/mechdwg.html

ORDERING INFORMATION

DS1670E

20-pin TSSOP

DS1670S

20-pin SOIC

DESCRIPTION

The Portable System Controller is a circuit, which incorporates many of the functions necessary for low

power portable products integrated into one chip. The DS1670 provides a Real Time Clock, NV RAM

controller, microprocessor monitor, and a 3-channel, 8-bit analog-to-digital converter. Communication

with the DS1670 is established through a simple 3-wire interface.

The Real Time Clock (RTC) provides seconds, minutes, hours, day, date, month, and year information

with leap year compensation. The RTC also provides an alarm interrupt. This interrupt works when the

DS1670 is powered by the system power supply or when in battery backup operation so the alarm can be

used to wake up a system that is powered down.

CEOH

pins. The backup energy source used to power the RTC is also used to retain RAM data in the

controlled during power transients to prevent data corruption.

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

ST

X1

X2

AIN0

AIN1

AIN2

RST

BLE

BHE

SCLK

I/O

CS

CEI

CEOL

CEOH

INT

GND

20-Pin TSSOP (4.4mm)

20-Pin SOIC (300 mil)

DS1670

Portable System Controller

www.dalsemi.com